Airships would probably be much fast than cargo ships though. Ships cut through the water at like maybe 30 mph in good conditions. Airships could easily keep as they are dealing with so much less drag. In the 1930 they moved at like 70 mph aka 2x the speed of container ships. I mean there cargo space would be like 1/40 but with the difference in speed thats only 1/20 in the rate of moving cargo not to mention that you aren't bound by water which is the major issue with ports. They are just very congested and ships are stuck in ship lanes. The air is much more limitless in terms of shipping paths.

> Ships cut through the water at like maybe 30 mph in good conditions.

Container ships rarely if ever go that fast. Usually it’s in the 15-18 knots range (aka <20mph) from what I’ve seen.